The Tassajara Fire was contained fully last week and is now completely out. It was more than all fires in offices put together. After speaking with the fire chief in that area, I went out to fly my drone and see what I could do to help document the situation. On my first trip out I had not cached the mapping data on my tablet before driving out of range for cellular service, so I had to fly manually to gather data. The area looks like a bomb went off. The fire burned everything in many areas, including homes and other structures. Nothing but foundations and ashes are left in many cases.
I flew 3 maps, with 2 of them being adjacent to one another and the other 1/4 mile down the road. The first map has finished processing the stitched Orthomosaic, Digital Surface, and the 3D model maps in just a few hours. The dataset was extremely large at 305 images.
I am using the Drone Deploy Mapping Engine Beta to process my images. It uses the images that I took with my DJI Phantom 3 Professional, and the Photogrammetric, GPS sensor data that are recorded with them, to calculate projected elevation models. In simpler terms, this process allows us to see the imagery as photorealistic 3 dimensional model.
Being able to visualize a 3 dimensional terrain is important when mapping an area that was recently devastated by a hot fire, like this area. The fire burned all the vegetation in some areas, leaving nothing but loose dirt and ash. The rainy season is just starting this month, and erosion will be a huge issue for this area, now that the vegetation is gone.
Using the Digital Surface Heat Map and the 3D Model, areas of potential erosion and flooding can be predicted. The resulting information could be used to help prepare for the coming rains. The imagery can also show the passing of time, if it was to be imaged again in a year. You could then see, what has grown back, or where erosion occurred during the time between mappings.
Article written and dataset captured by George Krieger,
Processing of imagery and resulting maps by Drone Deploy www.dronedeploy.com
For reference Cal Fire has this map of the fire perimeter https://email@example.com,-121.5845236,14z/data=!4m2!6m1!1szp8nK_5H0MFQ.kzTmU5XK-qJQ